A Dipeptide-derived Dansyl Fluorescent Probe for the Detection of Cu in Aqueous Solutions.

A novel dansyl-based fluorescent probe (DG) was designed via the introduction of a dipeptide, glycyl-L-glutamine. DG showed good selectivity and sensitivity towards Cu in aqueous solutions in the pH span of ~ 6-12. The coordination of Cu with the dipeptide moiety led to the fluorescent quenching of the dansyl fluorophore. The association constant value for Cu was 0.78 × 10 M in a 1 to 1 stoichiometric ratio. The detection limit in HEPES buffer solution (10 mM, pH 7.4) was 1.52 µM. DG also showed strong anti-interference capability in the presence of other metal ions. It was worth noting that DG maintained the detection ability towards Cu in real water samples and cell imaging, implying the potential application opportunities in complicated environments.